[Development] Automatically abandoning cherry-picks for closed branches?

[Christian Ehrlicher]

Hi,

I wonder if we could have a bot which automatically closes cherry-picks 
for branches which are closed. Currently there are 108 open cherry-picks 
from which only ~20 are for an still open branch:
https://codereview.qt-project.org/q/owner:cherrypick_bot%2540qt-project.org+is:open+repo:qt/qtbase

And what to do with stalled cherry-picks? There are some which have 
should go into 6.8 but waiting to be integrated into 6.9 which is closed 
now, for example https://codereview.qt-project.org/c/qt/qtbase/+/641073


Christian